Ground Signals - Where are they used?

Re:Ground Signals - Where are they used? (New Haven Neil)

Thu, 11 Mar 2010 08:42:17 GMT

It says its Stirling - Jocklandia.

I'd agree with your assessment, Gordon!

Re:Ground Signals - Where are they used? (Nodrog1826)

Thu, 11 Mar 2010 08:01:46 GMT

whatlep

New Haven Neil

It's one of these - not floodlit, old fashioned oil lamp!

Interesting photo. Where is it?

Not sure as to its location, as its a link from the signal page you posted, some of the drawings have a camera symbol next to them and that takes you to a relevent photo.

As for the signal, my understanding is that it could be ignored by anything going into a Headshunt, which is what it the siding appears to be from the photo..

Re:Ground Signals - Where are they used? (whatlep)

Wed, 10 Mar 2010 23:18:03 GMT

New Haven Neil

It's one of these - not floodlit, old fashioned oil lamp!

Interesting photo. Where is it?

Re:Ground Signals - Where are they used? (whatlep)

Wed, 10 Mar 2010 16:40:44 GMT

LTfan

Some railways used a floodlit disc rather than one with a red or yellow stripe.

(snip)

Nice example of an LT calling on signal!

To answer an earlier post, the yellow bar on a black disc is exactly the same as yellow bar on white disc in terms of purpose. It was intended for use where the signal would be floodlit, rather than backlit. Black background colour was used so the yellow band would appear more clearly at night under the floodlight. See here for more: http://www.railsigns.co.uk/sect3page4/sect3page4.html

Re:Ground Signals - Where are they used? (New Haven Neil)

Wed, 10 Mar 2010 11:06:45 GMT

Yes, it's one of those Gordon! Brand new, never been used. It was a gift many moons ago from an S&T man at Bishop Auckland together with a normal coloured one which is distinctly used!

Re:Ground Signals - Where are they used? (Nodrog1826)

Wed, 10 Mar 2010 07:50:19 GMT

Appologies for the grainy pic

This could be the type NHN is refering to,
[attachment=0]

Was placed on top of a crossing gate post, no loco could pass it unless it was going into Nos 1 or 3 roads,
technically a headshunt for rope hauled trains.

Rope hauled trains could ignore it ast the line was set for the head shunt by electric interlocing.

Mind you as the hauler driver I could not see the signal as the engine was almost a mile away!!!!!!

Re:Ground Signals - Where are they used? (New Haven Neil)

Tue, 09 Mar 2010 19:43:32 GMT

I'm interested to see the white with yellow stripe disc signals - I have a genuine 12 inch to the foot black with yellow stripe disc, is that the same thing? It's ex-north eastern region, if it's a regional variation?

Re:Ground Signals - Where are they used? (PaulRhB)

Tue, 09 Mar 2010 19:12:29 GMT

whatlep

though the red disc at the left hand end of the left hand station is unnecessary.

The left end disc should really be a calling on but there are a few examples of a disc being used. I put it in to allow more shunt moves onto a train.

whatlep

Similarly for the engine shed road and associated siding on which a yellow disc could be placed (facing the shed).

I assumed the two sidings and Loco shed were handpoints within the yard. Just the one dummy to control the exit for all three.

whatlep

Do we assume that the siding bottom left is operated off a ground frame and hence unsignalled?

I would as it's probably a industrial siding and too remote to the nearest box to be fully signalled.

Need a Signalbox at each station too.

Re:Ground Signals - Where are they used? (whatlep)

Tue, 09 Mar 2010 17:59:56 GMT

PaulRhB

Bear in mind this is a little over the top for most narrow gauge lines so you could easily lose the distant signals if line speeds are low. (snip)

Yes, that would do nicely, though the red disc at the left hand end of the left hand station is unnecessary. Do we assume that the siding bottom left is operated off a ground frame and hence unsignalled? If not, that needs exit/entry signals too. Similarly for the engine shed road and associated siding on which a yellow disc could be placed (facing the shed).

Fun, ain't it!

Re:Ground Signals - Where are they used? (PaulRhB)

Tue, 09 Mar 2010 15:34:08 GMT

Bear in mind this is a little over the top for most narrow gauge lines so you could easily lose the distant signals if line speeds are low. The taller of the two arms on the bracket signals indicates the main route, (usually the straighter one).
All signals are on the left as main line practice but if your drivers are on the right then so would your signals if they want good visibility.

[attachment=0]

Re:Ground Signals - Where are they used? (whatlep)

Mon, 08 Mar 2010 22:01:41 GMT

C&S

(snip)I believe that unlike a red/white ground signals that could not be passed when set to Danger, these were used at the exit to a set of sidings, where there was a headshunt that extended beyond the signal. When OFF the signal gave clearance to enter the main line, when ON it could be passed to run into the headshunt.

Yep, that's the general idea. Technically, a yellow shunting signal can be passed when not clear for any movement "in a direction for which the signal, when cleared, does not apply" (BR 1972 Rule Book C 3.2.4 if anyone cares!). There were colour light examples of "yellow discs" too. They were usually used where moves within a yard needed to be made over points which led to a running line and having to signal every move would be a distraction the signalman. Popular with the bean counters since each signal operated added to a signalbox's 'lever pull' count which affected the box/ payment grade. Yellow disc= few pulls!

On the other hand, the Byzantine rule wording with its requirement for clear understanding on all drivers' parts about which routes were which and the general undesirability of passing a signal at danger made yellow discs extremely unpopular with the operating department! In some places, yellow discs were replaced by multiple red (standard) shunt discs so that the driver received a positive indication that he was OK to proceed. To appease the bean counters, there was usually an instruction that the red discs for moves within the yard could normally be left at 'clear' unless required to be set to danger - a reversal of normal signalling practice.

Here's some discs at the former Ordsall Lane No.4 box just west of Manchester. Yellow disc on the left, two red discs (which could also have been a yellow disc) on the right.

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Re:Ground Signals - Where are they used? (Woderwick)

Mon, 08 Mar 2010 21:50:51 GMT

Oh this is an old pic of LBSCR rotating signsls for your interest

Re:Ground Signals - Where are they used? (Walts-Playmobil)

Mon, 08 Mar 2010 21:43:47 GMT

The ground signal with yellow and white lights is still in use. It may be used when there is a shutting neck. The train can pass it into the shutting neck any time. If however the train is going into the main line the points will be pulled over and the signal cleared for the train to proceed. This is to save the signal man having to clear the signal every time the train is required to go into the shutting neck.
There was also a full size signal with a square end (same as a home signal) that was painted yellow with a black strip. That saved the same purpose.

Re:Ground Signals - Where are they used? (C&S)

Mon, 08 Mar 2010 18:59:34 GMT

Just for the sake of completeness - the Southern Region had a variant of a small lower-quadrant semaphore arm on a ground-level post, this was yellow with a black vertical stripe. Sometimes a similarly coloured disc was used, although this had a horizontal stripe. At one location known to me, the exit to Feltham yard in SW London, it was a full-sized signal. I think they showed either amber or green at night.

I believe that unlike a red/white ground signals that could not be passed when set to Danger, these were used at the exit to a set of sidings, where there was a headshunt that extended beyond the signal. When OFF the signal gave clearance to enter the main line, when ON it could be passed to run into the headshunt.

Re:Ground Signals - Where are they used? (whatlep)

Fri, 19 Feb 2010 23:30:17 GMT

Bearing in mind your track plan Gareth, this diagram of the signalling at Highley (Severn Valley) may be helpful:
http://www.svrsig.org/svr/Frame6.htm

To go into a bit of detail.....

flyingsignalman

whatlep

(snip)You could use the ground discs for any of the following purposes:
1) Calling-on: 2) Shunt-ahead: 3) Warning: 4) Shunting
(snippety snip)

In the instances mentioned above a subsidiary signal (in the form of a miniature semaphore signal under the main arm) would normally be provided rather than a disc signal.
(snip)

Generally true, I agree, for items 1-3 which are indeed subsidiary signals, but there is nothing in the rules to prevent them being a disc signal. See examples from UK railways here: http://www.railsigns.co.uk/sect4page2/sect4page2.html.

Even today you can visit Worcester Shrub Hill and see a large shunting disc used as a main signal with a conventionally sized disc beneath it labelled as a calling on signal. As ever, there is a prototype for everything. See http://anoraksia.ukgeeks.co.uk/c717174.html

Item 4 would normally be a ground disc as it is distinct from a subsidiary signal, but equally there were plenty of examples of miniature arms. See same links.

Re:Ground Signals - Where are they used? (flyingsignalman)

Fri, 19 Feb 2010 20:30:26 GMT

whatlep

(snip)You could use the ground discs for any of the following purposes:
1) Calling-on: admitting a train into a section of line already occupied by a previous train (usually at a station)
2) Shunt-ahead: what it sounds like, but with inherent implications about block working
3) Warning: line is clear only as far as the next stop signal (again associated with specific types of block working)
4) Shunting

In the instances mentioned above a subsidiary signal (in the form of a miniature semaphore signal under the main arm) would normally be provided rather than a disc signal.

You could site a ground disc at either end of the station loop. Another could be placed leading from the sidings at the station reading to the main lines.

Re:Ground Signals - Where are they used? (3Valve)

Wed, 17 Feb 2010 16:44:06 GMT

Brain sufficiently fried thanks Peter.

Track plan as requested Trevor.

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Re:Ground Signals - Where are they used? (whatlep)

Wed, 17 Feb 2010 16:25:13 GMT

3Valve

(snip)Could someone with infinately more knowledge than me educate me in the use of ground signals please, so I have some idea where to put mine.
(snip)

Basic answer is to provide a signalled manoeuvre that is not otherwise provided for by main stop signals (e.g. semaphore homes) on "running lines" (think main movements). So you need to provide a diagram and think about which routes would require "running" signals and which would not.

You may find this site helpful: http://www.signalbox.org/

You could use the ground discs for any of the following purposes:
1) Calling-on: admitting a train into a section of line already occupied by a previous train (usually at a station)
2) Shunt-ahead: what it sounds like, but with inherent implications about block working
3) Warning: line is clear only as far as the next stop signal (again associated with specific types of block working)
4) Shunting

Item (4) is probably most likely for most G-scalers, so I'll quote directly from the BR 1972 Rule Book (clause C.3.2.4 if you care!):
"Shunting signals govern the passage of a train from a siding to a running line, from a running line to a siding, between one running line and another, and control shunting operations." "When cleared, shunting signals authorise Drivers to proceed as far as the line is clear".

In case the last sentence doesn't sound logical, normally in the UK a cleared stop signal indicates the line is clear to the next stop signal with no obstructions possibly in the way. A driver passing a cleared shunting signal MUST expect the possibility of an obstruction before the next stop signal.

End of lesson! PM me if your brain needs more serious frying or just for an opinion on where you need main/shunting signals!

Re:Ground Signals - Where are they used? (Round n Round)

Wed, 17 Feb 2010 14:21:12 GMT

Hi Gareth

32 years in to job before they retired /(disposed of) me.

Happy to offer advice but could you send me a track plan then I can suggest some locations for your ground signals.

Cheers, Trevor.

Re:Ground Signals - Where are they used? (3Valve)

Wed, 17 Feb 2010 14:08:09 GMT

Nice one don. Thanks for the link.